I'm using SQL Server 2016 to return json data in a string field in my data set. I passed the json string to the model without any conversions. I want to enumerate my json string field in MVC razor like:
#foreach (var notification in Model.AccountSettings.EmailNotifications)
{
EmailNotifications is a json array of objects.
EmailNotifications = [{"EmailNotificationID":8,"EmailNotificationName":"Any new KLAS report is published.","IsSet":false},{"EmailNotificationID":9,"EmailNotificationName":"KLAS publishes a report in one of my areas of interest.","IsSet":false}]
What the best way to do this?
The clean solution is to create a class to represent each item in your JSON array, convert your string to a list of this class and enumerate that.
public class NotificationItem
{
public int EmailNotificationID { get; set; }
public string EmailNotificationName { get; set; }
public bool IsSet { get; set; }
}
And you may use Newtonsoft.Json.JsonConvert.DeserializeObject method to convert the json string to list of NotificationItem objects.
#{
var items = Newtonsoft.Json.JsonConvert
.DeserializeObject<List<NotificationItem>>("yourJsonStringHere");
}
#foreach (var item in items)
{
<p>#item.EmailNotificationID</p>
<p>#item.EmailNotificationName </p>
}
Related
Using .Net core 2.2, I am building an API that returns JSON data from my stored procedure (using FOR JSON PATH), I return a value that looks like:
[{"ID":213,"SizeCode":"Small"},{"ID":257,"SizeCode":"S/M"},{"ID":214,"SizeCode":"Medium",},{"ID":215,"SizeCode":"Large"}]
So when I map it to my object to return from the API
public class Details
{
public string SizeChart { get; set; }
}
,it returns this:
"[{'ID':213,'SizeCode':'Small'},{'ID':257,'SizeCode':'S/M'},{'ID':214,'SizeCode':'Medium',},{'ID':215,'SizeCode':'Large'}]"
I don't want the double quotes around it, so I figure the actual property shouldn't be a string. Is there a better data type to use or a way to return without the double quotes?
You need to parse string into JSON object (actually in your case - JArray as it is an array) and return it from your API:
JArray a = JArray.Parse(jsonString);
So it might look like
public class Details
{
public string SizeChart { get; set; }
public JArray SizeChartJArray {
get {
return JObject.Parse(SizeChart);
}
}
}
I am trying to create an IEnumerable from an HttpPost request.
The JSON in the body reads as follows:
[{"id":15496,"order":0},{"id":15500,"order":1},{"id":15503,"order":2}]
The post request is like so:
[HttpPost("[action]")]
public IActionResult SendReorderRows([FromBody] IEnumerable<ReorderRow> rows){
foreach(var row in rows){
Debug.WriteLine(row.id);
}
}
The referenced class is here:
public class ReorderRow
{
public int id;
public int order;
}
However when I run this example it gives me the
Object reference not set to an instance of an object
error for "rows".
I'm having difficulty finding a basic way to parse JSON and convert it to an IEnumerable for use in the API. Am I missing something straightforward?
Use an array instead.
[HttpPost("[action]")]
public IActionResult SendReorderRows([FromBody] ReorderRow[] rows) {
foreach(var row in rows){
Debug.WriteLine(row.id);
}
}
It will bind to the JSON array.
You also need public properties in the object model in order for them to be properly populated when binding the objects.
public class ReorderRow {
public int id { get; set; }
public int order { get; set; }
}
Reference Model Binding in ASP.NET Core : How model binding works
I am sending a Json Array from the client web application to asp.net webapi.
For example,
{
"SurveyId":3423,
"CreatorId":4235,
"GlobalAppId":34,
"AssociateList":[
{"AssociateId":4234},
{"AssociateId":43},
{"AssociateId":23423},
{"AssociateId":432}
],
"IsModelDirty":false,
"SaveMode":null
}
Here Associate List is a JSON Array,
Usually it will automatically serialize to a List<> object.
Using the below code ,i am posting the response to the WebApi
public IEnumerable<Associate> Post(ResponseStatus responseStatus)
{
return this.responsestatusrepository.ResponseStatusCheck(responseStatus);
}
The ResponseStatus class is shown below.
public class ResponseStatus : AppBaseModel
{
public int SurveyId { get; set; }
public int CreatorId { get; set; }
public int GlobalAppId { get; set; }
public List<Associate> AssociateList { get; set; }
}
I have changed the List<> to Collection<> as a part of my code analysis correction.
ie, public Collection<Associate> AssociateList { get; set; }
But it is always getting a null value when we are using collection instead of List. Is there any specific reason for this?
Ok, I think I will have to answer this in an indirect way.
What you are passing on to the server is an array of objects (in JSON format), but once you start processing this in C# the array of objects is now treated as a single c# object. Inside this object, your model expects one of the fields to be a Collection of Associate.
Right, when I work with JSON data similar to whats mentioned in this case - I prefer to use Newtonsofts' JOject.
So here is how I made the C# object with the JSON data you provided:
Used your model:
public class ResponseStatus
{
public int SurveyId { get; set; }
public int CreatorId { get; set; }
public int GlobalAppId { get; set; }
public Collection<Associate> AssociateList { get; set; }
}
public class Associate
{
public int AssociateId { get; set; }
}
Made a routine which takes string (the JSON data), and returns an object of type ResponseStatus:
using System;
using System.Collections.Generic;
using Newtonsoft.Json.Linq;
---------------------------------------------------------------------
public static ResponseStatus GetResponseStatusObject(string jsonData)
{
JObject jObject = JObject.Parse(jsonData);
return jObject.ToObject<ResponseStatus>();
}
Now when I call this method and pass on the exact same JSON data which you provided, I get this:
This might not directly solve your problem, but hopefully guide you in the right direction in understanding array/object serialization when working with JavaScript/C#.
Best of luck!
As part of my WCF service, i convert my DataTable into a JSON. On client side, I want to able to convert this JSON response into a .NET collection. I want to be able to keep it dynmaic, and bind it to a data grid. I am trying figure out the best way to do this. Thanks jay
Define a collection and a class whose properties match the JSON data - then use the JavaScriptSerializer class. Then just bind your grid to the collection:
class ACollection
{
public IEnumerable<SomeClass> SomeClassList { get; set; }
}
class SomeClass
{
public string Field { get; set; }
}
JavaScriptSerializer jsSerializer = new JavaScriptSerializer();
ACollection list = jsSerializer.Deserialize<ACollection>(jsonString);
I want to use .Net Framework built-in library to convert my DataTable / DataSet to JSON. How is this possible.
DataTable and DataSet objects cannot be JSON serialized directly. You'll need to convert them first to something like
IDictionary<string, IEnumerable<IDictionary<string, object>>>
Once you do that, you can use JavaScriptSerializer to do the actual conversion to JSON.
Update based on your comment:
If you are trying to convert the data obtained from a SQL query into JSON, represent the data in a simple class first:
public class Employee
{
public int EmployeeID { get; set; }
public string FirstName { get; set; }
public string LastName { get; set; }
}
Read the results into:
List<Employee>
Now, convert the list to JSON using JavaScriptSerializer.